To explore how airborne microbial patterns change with height above the Earth's surface, we flew NASA's C-20A aircraft on two consecutive days in June 2018 along identical flight paths over the US Sierra Nevada mountain range at four different altitudes ranging from 10,000 ft to 40,000 ft. Bioaerosols were analyzed by metagenomic DnA sequencing and traditional culturing methods to characterize the composition and diversity of atmospheric samples compared to experimental controls. The relative abundance of taxa changed significantly at each altitude sampled, and the diversity profile shifted across the two sampling days, revealing a regional atmospheric microbiome that is dynamically changing. the most proportionally abundant microbial genera were Mycobacterium and Achromobacter at 10,000 ft; Stenotrophomonas and Achromobacter at 20,000 ft; Delftia and Pseudoperonospora at 30,000 ft; and Alcaligenes and Penicillium at 40,000 ft. Culturebased detections also identified viable Bacillus zhangzhouensis, Bacillus pumilus, and Bacillus spp. in the upper troposphere. to estimate bioaerosol dispersal, we developed a human exposure likelihood model (7-day forecast) using general aerosol characteristics and measured meteorological conditions. By coupling metagenomics to a predictive atmospheric model, we aim to set the stage for field campaigns that monitor global bioaerosol emissions and impacts. Aerosols (mostly desert dust, black carbon and ocean spray) regularly disperse across the Pacific Ocean with springtime atmospheric winds-in fact, models suggest that as much as 64 Teragrams of Asian aerosols can be transported to North America annually 1. Past studies have reported microorganisms co-transported with globally-dispersed aerosols, and that both DNA signatures and viable cells can be detected in air masses 2-4. For example, thousands of taxonomic signatures were measured in springtime Asian dust plumes delivering free tropospheric bioaerosols to an alpine research station in central Oregon 3. In a separate flight project surveying airborne microorganisms in the western region of the United States, several taxa were found to be enriched in the upper atmosphere, including bacterial families Lachnospiraceae, Ruminococcaceae and Erysipelotrichaceae 2. Despite harsh conditions in the atmosphere, viable bacterial isolates were recovered from the same study 2 , including Bacillus sp., Micrococcus sp., Arthrobacter sp. and Staphylococcus sp. Previous aerobiology campaigns using aircraft were flown at single altitudes in order to refine collection methods and demonstrate some of the first measurements of an atmospheric microbiome 2,5-7. To date, there are only a few studies that have examined microbiological changes across a vertical gradient in Earth's troposphere 8-10. More studies using advanced genomic techniques such as shotgun metagenomic sequencing will be essential to formulating predictive models of bioaerosols and how the atmospheric microbiome is influenced by meteorological
High-altitude balloons (HABs) present a valuable and cost-effective tool for educators and students to access the conditions that are analogous to space and extraterrestrial environments in the Earth’s upper atmosphere. Historically, HABs have been used for meteorological measurements, observation, sampling of aerosols, and exposure of samples to upper atmosphere environments. The Earth’s stratosphere allows researchers access to a unique combination of wideband solar radiation, extreme cold, rarefied air, low humidity, and acute ionizing radiation—conditions that are relevant to space biology research. Here, we describe a reproducible payload for a HAB mission that can be constructed, launched, and retrieved for about $3,000. This general standard operating procedure can be used by educators, community scientists, and research teams working with limited resources.
under a contract with the National Aeronautics and Space Administration (80NM0018D0004).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.